Some of the comments in this thread (http://www.briskoda.net/forums/topic/287713-17s-or-18s-for-winter-wheels/) started me thinking.

There is no doubt that for best grip in snow and heavy rain, narrow tyres are always better, regardless of profile or sidewall height.

But with regard to diameter: is there any reason at all for ever wanting larger wheels / lower profile tyres, other than purely cosmetic ones?  The only exception is the VRS models where, I understand, larger brake disks require a larger wheel diameter.

I have never heard any claim (from road testers or manufacturers) that big wheels / low profile tyres offer better grip or better handling, but I hear consistent comment from road testers - even the most enthusiastic "sporting" ones - when testing everything from Aston Martins to Ford Fiestas - like "unfortunately our road test sample car had been fitted with the optional 20" Megabling wheels [presumably for the benefit of the photographer] which made the ride harsh although they did not sifgnificantly improve the roadholding ..."

I regard a diesel estate car (any diesel estate car) as a practical workhorse, not a status symbol for posing in or impressing the neighbours (I'm still immature enough to have a sports car for doing that!).  OK, I don't want even an everyday workhorse to be any more ugly than it has to be, but personally (and of course it is a personal thing) I don't find that bigger wheels look any better than standard ones, however elaborate (and hard-to-clean) the design is.  If anything, I usually find that the simpler the design of a wheel the more elegant it looks.  And talk of "filling the wheel arches" doesn't seem to make much sense, since after fitting the necessary low-profile tyres, the overall diameter ends up exactly the same.  But maybe it's just my prejudice. 

Edited 12 October, 201312 yr by Stuarted

My little brother studied motorsport engineering at uni before working in r&d at bmwmini and one of the first things they learned was wheel size made almost no difference to grip levels! Suspension setup was by far and away the most important factor!

That is interesting but logical - I presume you mean the overall wheel diameter / actual rolling radius?  Yes, I would expect the comfort to be affected by that (smaller diameter = more unconfortable as wheel falls deeper into bumps) but not the grip.

However on a production road car the overall wheel diameter (i.e., tyre outer diameter) is pretty much fixed anyway.

I was referring more to the greater rim diameter and associated lower-profile (lower sidewall height - and more expensive) tyres which some owners seem to be willing to spend huge amount of money on.  I really can't see the point.

Some of the comments in this thread (http://www.briskoda.net/forums/topic/287713-17s-or-18s-for-winter-wheels/) started me thinking.

There is no doubt that for best grip in snow and heavy rain, narrow tyres are always better, regardless of profile or sidewall height.

 

I'm not so sure.

 

I feel very safe with the 17" 205/40 Contis on my existing car.  Fling it around in all weather and it's glued to the tarmac.

 

I drove my mother-in-law's Ford Ka (13" 165/65) in heavy rain once and I'd never do so again.....the slightest manoeuvre and I was all over the place.

 

I feel very safe with the 17" 205/40 Contis on my existing car.  Fling it around in all weather and it's glued to the tarmac.

 

I drove my mother-in-law's Ford Ka (13" 165/65) in heavy rain once and I'd never do so again.....the slightest manoeuvre and I was all over the place.

It's not so much tyre width but tyre compound and as already stated suspension geometry/setup that is more critical.

I'm sure my Octavia will handle equally as well on 205's on 16 inch wheels as it does on the optional 225's on 18 inch wheels. I've no doubt the 16 inch wheels will be more comfortable and not as harsh.

Regards

Ted